Histological Evaluation of Periodontal Healing after Semilunar Coronally Positioned Flap Procedure

Abstract

The aim of this study was to evaluate the process of healing between the root planed surface and the soft tissue in the healing process after the semilunar coronally positioned flap procedure. Maxillary and mandibular 40 incisors of 8 beagle dogs were used in this study. Prior to the semilunar coronally positioned flap procedure, the gingival recession model was created. A partial-thickness flap of labial gingiva from the canine to the opposite canine was elevated and labial alveolar bone of the subject teeth was removed. Then, the coronal margin of the flap was removed and the flap was sutured at the apically position. Four weeks later, the semilunar coronally positioned flap procedure was performed according to Tarnow's procedure. After root planing, a semilunar incision was made following the curvature of the free gingival margin. A split thickness dissection was made from the initial incision line coronally. This was connected with an intrasulcular incision. The flap was coronally positioned to the CEJ. The tissue was held in place with moist gauze against the tooth for 5 minutes. Clinical observation and histological analysis were performed 0, 1, 2 and 4 weeks after surgery. Successful root coverages were clinically observed at all observation periods. According to histological observation, at week 0 (24 hours), the narrow space between the flap and root surface was filled with clot. Long junctional epithelial attachment had developed within one week, and then did not increase significantly. At week 4, 73.3±29.1% of the root planed surface was adjacent to the epithelium. The length of connective tissue attachment did not show a significant change. Slight root resorption was observed at weeks 1 and 2. New cementum formation was observed on 6.9±11.1% of the root surface. It was concluded that the semilunar coronally positioned flap procedure may produce long junctional epithelium on most of the root planed surface within one week, and limited cementum formation from week 2 to week 4.